Modify kpod diff --json to --format json

We want all kpod subcommands to use the formats code to output
formats like json.  Altering kpod diff --json to kpod diff --format json
like the kpod images command.

Signed-off-by: baude <bbaude@redhat.com>

docs/kpod-diff.1.md

@@ -13,9 +13,9 @@ Displays changes on a container or image's filesystem.  The container or image w
 
 ## OPTIONS
 
-**--json**
+**--format**
 
-Format output as json
+Alter the output into a different format.  The only valid format for diff is `json`.
 
 
 ## EXAMPLE
@@ -26,7 +26,7 @@ C /usr/local
 C /usr/local/bin
 A /usr/local/bin/docker-entrypoint.sh
 
-kpod diff --json redis:alpine
+kpod diff --format json redis:alpine
 {
   "changed": [
     "/usr",

docs/kpod-history.1.md

@@ -47,10 +47,8 @@ Valid placeholders for the Go template are listed below:
     Print the numeric IDs only
 
 **--format**
-    Pretty-print history of the image using a Go template
+    Alter the output for a format like 'json' or a Go template.
 
-**--json**
-    Print the history in JSON form
 
 ## COMMANDS
 
@@ -60,6 +58,8 @@ Valid placeholders for the Go template are listed below:
 
 **kpod history --format "{{.ID}} {{.Created}}" debian**
 
+**kpod history --format json debian**
+
 ## history
 Show the history of an image
 

docs/kpod-info.1.md

@@ -21,16 +21,16 @@ Information display here pertain to the host, current storage stats, and build o
 
 Show additional information
 
-**--json**
+**--format**
 
-Output as JSON instead of the default YAML",
+Change output format to "json" or a Go template.
 
 
 ## EXAMPLE
 
 `kpod info`
 
-`kpod info --debug --json | jq .host.kernel`
+`kpod info --debug --format json| jq .host.kernel`
 
 ## SEE ALSO
 crio(8), crio.conf(5)